Geothermal tank vault with transition fittings

ABSTRACT

A geothermal vault apparatus for use in a geothermal system includes a tank vault to enclose the one or more manifolds of the system. The tank vault includes a tank shell defining an interior volume (e.g., formed of fiber reinforced plastic material), an access opening to permit a person to enter the tank shell, and an arrangement of a plurality of transition fittings located in a cylindrical wall of the tank shell and configured to couple a plurality of energy transfer pipes (e.g., HPDE pipes) to a plurality of ports of the one or more manifolds enclosed within the tank vault.

BACKGROUND

The present invention relates generally to vaults for use in geothermal exchange systems, e.g., geothermal exchange systems including heat transfer piping in one or more fields, and other tank apparatus.

Various geothermal heating and cooling systems for providing space conditioning, including heating, cooling, and humidity control, are available. Such geothermal systems may also provide water heating, either to supplement or replace conventional water heating systems, pool heating and cooling, and refrigeration.

Many exemplary geothermal exchange systems have been described. For example, various systems are shown in U.S. Patent Application Publication No. 2007/0051492 A1, entitled “Ground Source Heat Exchange System,” to Ross, published 8 Mar. 2007; and in U.S. Pat. No. 5,992,507, entitled “Geothermal Community Loop Field,” to Peterson et al., issued 30 Nov. 1999.

A geothermal exchange system, at least in one embodiment, can generally be described as a system that simply transfers thermal energy (e.g., heat) from the ground or groundwater into a space (e.g., a space being conditioned during the winter months) and/or transfers thermal energy (e.g., heat) from the space (e.g., a space being conditioned in the summer months) back into the ground or groundwater. As the temperature of the ground or groundwater remains fairly constant throughout the year, ranging from, for example, about 35° to 65° Fahrenheit in northern latitudes, operating efficiencies are high year-round.

For example, in many instances, a geothermal exchange system may include a distribution system that distributes thermal energy within a space or object being heated or cooled (e.g., a fan and/or duct work that moves air through ducts to individual spaces and returns air as well, or a water distribution system); a ground or groundwater heat exchanger that absorbs thermal energy (e.g., heat) from the earth or water, or discharges thermal energy (e.g., heat) to the earth or water (e.g., piping in vertical wells or horizontal troughs); and a heat pump apparatus that transfers thermal energy between the distribution system and the ground or groundwater heat exchanger. For example, the geothermal heat pump apparatus may be a water source geothermal heat pump or a direct exchange (DX) heat pump. Water source geothermal heat pumps extract energy from the ground or ground water sources. The water source geothermal heat pumps can either be used in an open loop geothermal system or a closed loop geothermal system.

In the case of an open loop system, water from a water well, lake, river, pond or running spring (i.e., a water source) is generally piped to the heat pump apparatus. For example, the water may go through a heat exchanger inside the heat pump apparatus located next to a refrigerant compressor also inside the heat pump. The heat exchanger of the heat pump may include coil pipes containing the refrigerant (e.g., freon) that are wrapped with a coil containing the ground water piped to the heat pump apparatus. The ground water piped to the heat pump apparatus (e.g., typically around 50 to 60 degrees Fahrenheit) is used to modify the temperature of the refrigerant in coils of the heat exchanger of the heat pump apparatus. After the water is pumped from the water source through the water-to-refrigerant heat exchanger of the heat pump apparatus, the water is returned to the same or a different water source.

Closed loop systems are generally of two types, horizontal and vertical. In a horizontal closed loop system, a series of horizontal pipes (e.g., high density polyethylene (HDPE) pipes) is placed in the ground (e.g., fields of loops) and connected to the heat pump apparatus. For example, in such a closed loop system, a solution flowing through the closed loop may flow through a heat exchanger inside the heat pump apparatus located next to the refrigerant compressor. The closed loop may contain a solution (e.g., usually a water and anti-freeze solution (e.g., a solution containing a glycol component)). As the solution flows through the closed loop, and as such, through the buried pipes in the ground, the solution extracts the thermal energy from the ground and transfers it to the heat exchanger in the heat pump apparatus. Like the open loop system, the heat exchanger of the heat pump apparatus may include coil pipes containing the refrigerant (e.g., freon) that are wrapped with a coil containing the solution that is flowing in the closed loop. The solution flowing in the closed loop that has been modified by the ground is used to modify the temperature of the refrigerant in the coils of the heat exchanger of the heat pump apparatus.

A vertical closed loop system operates in substantially the same manner as the horizontal pipe closed loop system with one exception. In the vertical closed loop system, the pipes are placed vertically in bored holes in the ground. Generally, in such closed systems (e.g., in both the vertical and the horizontal closed loops), water or a water/antifreeze mixture in the pipes remains within the pipes for the life of the system.

With the onset of the “Green Movement” in the energy field, the use of ground source, geothermal heat pump applications for large commercial heating and air-conditioning projects is prevalent. Such applications include, for example, geothermal applications for schools, retail building spaces, and institutional facilities. For example, such projects may include use of one or more fields of piping in vertical wells (e.g., 200 feet to 300 feet vertical wells) or one or more fields of piping in horizontal trenches (e.g., multiple acres of horizontal loop fields). These fields vary in the number of wells (e.g., ranging from 20 to 2000 wells).

Generally, for example, such systems may utilize pipes (e.g., 1 inch pipes) that are inserted into a grouted well, or laid in horizontal trenches, to gather or transfer heat via a circulated fluid solution (e.g., glycol solution in the 1 inch pipes). In one or more configurations, these pipes may then be brought together near finish grade and tied together into circuit feeder lines (e.g., with the use of couplings and/or manifolds). These circuit feeder lines may be, for example, typically 2 inch, 3 inch, and 4 inch lines. Such circuit lines may be brought together at a central location in the well field. In many systems, polyethylene pipe, such as high profile high density polyethylene (HDPE) pipe, is used.

Polyethylene pipes are fairly well known in the art and have proven useful in a variety of applications for handling water and other liquids. Such pipes made from polyethylene are useful because they have many desirable properties including being sufficiently rigid and yet flexible and lightweight. Polyethylene pipe is abrasion and corrosion resistant both with respect to the liquids transported through the pipe and with respect to the environment to which the exterior of the pipe is exposed. While polyethylene pipe has characteristics that make it an excellent choice for piping in many different applications, and connecting two lengths of polyethylene pipe together may be performed by heat fusing or butt fusing the pipes together (e.g., welding the pipes together), connecting the polyethylene pipe to another pipe or to other structure formed of different material is generally problematic (e.g., connection a fiberglass tank used for any purpose).

Generally, when piping positioned in the wells is brought together at a central location, a vault is needed to house an assortment of valves, gauges, flushing ports, and/or any other equipment that may be needed for implementation of the geothermal exchange system. The material and method of construction used in these vaults has varied. For example, many conventional vaults have used steel structures, and/or have used pre-cast or cast-in-place concrete. Such vault implementations have various disadvantages. For example, some vaults need to be erected in situ or, in other words, built on-site (e.g., a manufactured manifold is delivered to the site and a vault is built on location about the manifold); use of certain vault materials may present leakage problems; certain vault materials (e.g., steel) may present problems associated with corrosion; certain sheet-type vault materials cannot withstand soil loads and/or traffic loads; and other vaults can only be used above ground level.

SUMMARY

One or more embodiments described herein provide tank vaults for geothermal applications that are resistant to applied forces, are corrosion resistant, and/or are resistant to leakage, as well as other tank apparatus having similar characteristics. For example, the tank vault may provide a non-buoyant, structurally sound, underground vault to provide a water tight area for maintenance and operation of, for example, a manifold system in a geothermal application. For example, a fiber reinforced plastic (FRP) tank vault (e.g., an underground fiberglass tank), alone or with one or more associated features, may provide a tank vault with an engineered and delivered ballast system utilizing dead men and a strap system; may provide a structural tank vault capable of operation under an H-20 traffic load; may provide a tank vault that can be pressure tested at a jobsite; may provide a tank vault that will house a pre-manufactured manifold which can be delivered to the jobsite as a complete unit; and may provide a tank vault that includes Category 1, gas industry standard, transition fittings where circuit lines or piping enter the tank vault.

In one embodiment of the present disclosure, a geothermal apparatus for use in a geothermal system (e.g., a geothermal system that includes a plurality of energy transfer pipes for transfer of energy from a ground source to a solution to be transported to a heat pump apparatus) is described. The geothermal apparatus includes one or more manifolds used in controlling the flow of the solution from the plurality of energy transfer pipes to the heat pump apparatus (e.g., the one or more manifolds include a plurality of ports) and a tank vault to enclose the one or more manifolds used to control the flow of the solution.

The tank vault may include a tank shell (e.g., a FRP tank shell that includes a cylindrical wall terminating in two dome-shaped ends and defining an interior volume), an access opening sized to permit a person to enter the tank shell; and an arrangement of a plurality of transition fittings located in the cylindrical wall of the tank shell and configured to couple the plurality of energy transfer pipes to the plurality of ports of the one or more manifolds enclosed within the tank vault. Each of the plurality of transition fittings may include a transition pipe (e.g., formed of at least a polymer material, such as HDPE) connectable to one of the plurality of energy transfer pipes and coupled to one of the plurality of ports of the one or more manifolds. Each transition fitting provides for a water tight seal at the cylindrical wall of the tank shell between the transition pipe and the cylindrical wall.

In one embodiment of the geothermal apparatus, the transition pipe of the transition fitting may include an inner wall defining an opening through the transition pipe (e.g., wherein the inner wall of the transition pipe includes at least high density polyethylene), and further wherein the transition pipe includes an outer wall facing opposite the inner wall (e.g., wherein the outer wall of the transition pipe comprises at least fiber reinforced plastic material). Further, at least a portion of the outer wall of the transition pipe is coupled to the cylindrical wall using fiber reinforced plastic material.

In one embodiment of the geothermal apparatus, the transition fitting may include a sleeve formed of a fiber reinforced plastic material or a metal material (e.g., a sleeve that includes an inner wall defining an opening through the sleeve with the inner wall of the sleeve being coupled to the transition pipe to provide a water tight seal therebetween). Further, in another embodiment, the transition fitting may include a flange extending about the sleeve non-orthogonal to the axis therethrough with the flange being coupled to the cylindrical wall of the tank shell using fiber reinforced plastic material.

Still further, in yet another embodiment, the transition fitting may include a sleeve formed of a metal material, an insert configured to be inserted into an opening of the transition pipe; the transition pipe being press fit between the insert and the sleeve. Further, a flange may be formed of a metal material extending about the sleeve non-orthogonal to the axis with the flange being coupled to the cylindrical wall of the tank shell using fiber reinforced plastic material.

Yet further, the transition fitting may include a sleeve formed of a metal material (e.g., the sleeve including an inner wall defining an opening through the sleeve along an axis thereof from a first end to a second to of the sleeve). The second end of the sleeve may be threaded with the inner wall of the sleeve being coupled to the transition pipe to provide a water tight seal therebetween. Further, the transition fitting includes a coupling extending from a first end to a second end (e.g., the coupling including an outer wall formed of a fiber reinforced plastic material and an inner wall defining an opening for receiving a portion of the transition pipe therein). The inner wall of the first end of the coupling is threaded to mate with the second end of the sleeve and the outer wall of the coupling is coupled to the cylindrical wall using fiber reinforced plastic material.

Still further, in another embodiment of the geothermal apparatus, the cylindrical wall extends along an axis of the tank shell between dome-shaped ends thereof. Multiple transition fittings of the plurality of transition fittings are linearly aligned along the cylindrical wall parallel to the axis of the tank shell.

Yet further, in one or more embodiments, the tank shell may be a single, double, or triple wall tank. Further, for example, the tank shell may be associated with one or more circumferential ribs spaced along an axis of the cylindrical wall of the tank shell.

A vault apparatus for use in a geothermal system is also described that includes a tank vault and transition fittings such as summarized above, but which does not include a manifold installed therein (in other words, the use of the tank vault described herein allows delivery of the vault with or without a manifold being enclosed therein).

A method of installing a geothermal vault apparatus for use in a geothermal system is also described. For example, the method may include delivering a geothermal vault apparatus to a site for installation, wherein the geothermal vault apparatus includes one or more manifolds used in controlling the flow of the solution from the plurality of energy transfer pipes to the heat pump apparatus and a tank vault enclosing the one or more manifolds used to control the flow of the solution (e.g., such as a tank vault summarized above). Thereafter, the geothermal vault apparatus is positioned into a hole at the site (e.g., a ballast system may also be used to provide a non-buoyant vault apparatus in the hole).

Still further, a tank apparatus (e.g., for holding fluids) for connection to one or more fluid transfer pipes is described herein (e.g., wherein each of the one or more fluid transfer pipes is formed of high density polyethylene material). The tank apparatus includes a tank shell having at least a cylindrical wall terminating in two ends (e.g., two dome shaped ends) and defining an interior volume (e.g., wherein the cylindrical wall includes fiber reinforced plastic material). The tank apparatus further includes one or more transition fittings located in the cylindrical wall of the tank shell and configured to couple the one or more fluid transfer pipes to the interior of the tank shell. Each of the one or more transition fittings includes a transition pipe connectable to one of the one or more fluid transfer pipes (e.g., wherein each transition fitting provides for a water tight seal at the cylindrical wall of the tank shell between the transition pipe and the cylindrical wall comprising the fiber reinforced plastic material). Further, the transition pipe of the transition fitting includes an inner wall defining an opening through the transition pipe (e.g., wherein the inner wall of the transition pipe comprises at least high density polyethylene), and further wherein the transition pipe includes an outer wall facing opposite the inner wall (e.g., wherein the outer wall of the transition pipe comprises at least fiber reinforced plastic material). Further, at least a portion of the outer wall of the transition pipe is coupled to the cylindrical wall using fiber reinforced plastic material.

In one more embodiments, the tank apparatus includes features such as those described with reference to the vault apparatus herein, for example, the tank shell may include a single, double, or triple wall shell or tank, and further wherein the tank shell may be associated with one or more circumferential ribs spaced along an axis of the cylindrical body of the tank shell.

The above summary of the present invention is not intended to describe each embodiment or every implementation of the present disclosure. Advantages, together with a more complete understanding of the disclosure, will become apparent and appreciated by referring to the following detailed description and claims taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a schematic drawing of an embodiment of a geothermal vault apparatus (e.g., including a tank vault) being used in a geothermal exchange system.

FIG. 2 is a flow diagram depicting some components used in the operation of an embodiment of a geothermal exchange system.

FIGS. 3A-3D show a perspective view, a top view, a side view, and an end view, respectively, of one exemplary embodiment of a tank vault that may be used in a geothermal exchange system such as shown in FIG. 1.

FIGS. 4A-3C show a top view, a side view, and a cross-sectional view taken along line 4C-4C of FIG. 4B, respectively, of the tank vault shown in FIGS. 3A-3D with additional detail with regard to components (e.g., a manifold) within the tank vault.

FIG. 5 shows a perspective view of one exemplary transition fitting that may be used in a tank vault for a geothermal exchange system.

FIG. 6 shows a side view of a portion of the exemplary transition fitting shown in FIG. 5 that may be used in a tank vault for a geothermal exchange system.

FIG. 7 shows a cross-sectional view of a portion of the exemplary transition fitting shown in FIG. 5 that may be used in a tank vault for a geothermal exchange system.

FIG. 8 shows a front perspective view of another exemplary transition fitting that may be used in a tank vault for a geothermal exchange system.

FIG. 9 shows a side view of the exemplary transition fitting shown in FIG. 8 that may be used in a tank vault for a geothermal exchange system.

FIG. 10 shows a cross-sectional view of a portion of the exemplary transition fitting shown in FIGS. 8-9 used in a tank vault wall for a geothermal exchange system.

FIG. 11 shows a perspective view of yet another exemplary transition fitting that may be used in a tank vault for a geothermal exchange system.

FIG. 12 shows a perspective view of still yet another exemplary transition fitting that may be used in a tank vault for a geothermal exchange system.

FIG. 13A-13B shows a perspective view and a side view (e.g., installed) of still yet another exemplary transition fitting that may be used in a tank vault for a geothermal exchange system, or any other tank apparatus.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

In the following detailed description of illustrative embodiments, reference is made to the accompanying figures of the drawing which form a part hereof, and in which are shown, by way of illustration, specific embodiments which may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from (e.g., still falling within) the scope of the disclosure presented hereby.

Exemplary apparatus shall be described with reference to FIGS. 1-13. It will be apparent to one skilled in the art that elements from one embodiment may be used in combination with elements of the other embodiments, and that the possible embodiments of such apparatus using combinations of features set forth herein is not limited to the specific embodiments shown in the Figures and/or described herein (e.g., any elements of any of the embodiments may be used in combination with elements of other embodiments, or used not only in a vault apparatus, but also in any tank apparatus). Further, it will be recognized that the embodiments described herein may include many elements that are not necessarily shown to scale. Still further, it will be recognized that the size and shape of various elements herein may be modified but still fall within the scope of the present disclosure, although one or more shapes and/or sizes, or types of elements, or materials with which such elements are formed, may be advantageous over others.

FIG. 1 shows a schematic drawing of an exemplary embodiment of a geothermal vault apparatus 12 being used in a ground source geothermal exchange system 10. For example, as shown in FIG. 1, the geothermal exchange system 10 includes a heat pump apparatus and other related system components 14 that operate using the exchange of energy (e.g., a water source heat pump or direct exchange heat pump, other energy distribution system components, etc.). Further, the geothermal exchange system 10 includes a ground based heat exchange system 15 coupled to the heat pump apparatus 14. The ground based heat exchange system 15 includes the geothermal vault apparatus 12 and the flow circuit system 16. As generally shown in FIG. 1, one or more energy transfer pipes of the flow circuit system 16 are coupled to a plurality of transition fittings 30 of the tank vault 20. The transition fittings 30 provide a water tight seal at the wall of the tank vault 20 for the one or more energy transfer pipes.

For example, and clearly not limited thereto, the ground based heat exchange system 15 provides a closed recirculating loop when connected to the heat pump apparatus 14 and includes an upstream manifold and a downstream manifold (not shown in FIG. 1, as they are contained within tank vault 20 of geothermal vault apparatus 12). The upstream and downstream manifolds are positioned within the interior of the tank vault 20 as part of the geothermal vault apparatus 12 of the geothermal exchange system 10. The tank vault 20 may be positioned above ground; however, use of a tank vault 20 as described herein, also allows the tank vault 20 to be provided underground, as well as being used in either in open or closed loop geothermal systems.

The ground based heat exchange system 15 includes heat exchange flow circuit system 16 formed of a series of flow circuits, for example, 16 a-16 f, connected between the upstream and downstream manifolds. The flow circuits 16 a-16 f may be formed of piping, such as flexible plastic tubing (e.g., polyethylene pipe) as described further herein. As used herein, tubing and piping are used interchangeably.

As shown in FIG. 1, each flow circuit 16 a-16 f extends from the upstream manifold in the tank vault 20 through a wall of the tank vault 20, into the ground and returns through the wall of the tank vault 20 to the downstream manifold (e.g., through use of one or more couplings or manifolds 17 and circuit feeder lines 19). For example, three flow circuit loops 16 a-16 c are coupled together through a manifold 17 a to a circuit feeder line 19 a; the circuit feeder line 19 a then being coupled to a transition fitting 30 of tank vault 20. The other end of the loops 16 a-16 c are coupled together through manifold 17 b to circuit line 19 b that is coupled to another transition fitting 30. Further, for example, three other flow circuit loops 16 d-16 f are coupled together through a manifold 17 c to circuit feeder line 19 c; the circuit feeder line 19 c then being coupled to a transition fitting 30 of tank vault 20. The other end of the loops 16 d-16 f are coupled together through manifold 17 d to circuit line 19 d that is coupled to another transition fitting 30. As generally represented by schematic boxes 21 and lines 23, and as described herein, any number of and configuration of flow circuit loops may be used and connected to transition fittings 30 of the tank vault 20.

Heat exchange solution, such as water, an antifreeze mixture or a glycol solution, flows in each flow circuit 16 a-16 f. As the heat exchange solution flows through each flow circuit 16 a-16 f, the heat exchange solution exchanges energy with the ground and changes temperature. Depending upon whether the heat pump apparatus 14 is being used for cooling or heating, the heat exchange solution can be heated or cooled by the ground. The downstream manifold provides the cooled or heated heat exchange solution to the heat pump apparatus 14 through an input line 60 for heat exchange (e.g., in a heat exchanger within the heat pump apparatus 14). An output line 58 returns the heat exchange solution from the heat pump apparatus 14 (e.g., after heat exchange in the heat pump apparatus 14 where heat is added or removed from the heat exchange solution by the heat pump apparatus 14). Further, for example, a pump system may be included in the geothermal exchange system 10 (e.g., for pumping the heat exchange solution therethrough).

The downstream and upstream manifolds (e.g., such as the one or more manifolds 90 shown in FIGS. 4A-4C) are positioned in the tank vault and may be associated with one or more various components therein. For example, other components of the geothermal system 10 that may be located within the tank vault 20 or outside thereof, may include flow adjusters, sensors, control valves, gauges, flushing ports, control electronics, processing equipment, pumps, circuit setter valves, etc. In other words, generally, the tank vault 20 may be used to house any assortment of valves, gauges, flushing ports, and/or any other equipment that may be needed for implementation of the geothermal exchange system 10. FIG. 2 shows a block diagram of exemplary components of a geothermal exchange system 10 that may be housed within the tank vault 20, including, for example, an upstream manifold 92 (e.g., as well as flow or temperature sensors, and/or control valves, associated with the manifold), a downstream manifold 93 (e.g., as well as flow or temperature sensors, and/or control valves, associated with the manifold), one or more controllers 42, pumps 36, and/or one or more other computers 65 (e.g., to control and/or monitor one or more functions of the geothermal exchange system 10).

One exemplary configuration of a flow circuit system 16 is shown in FIG. 1. However, the flow circuit system to be connected to the manifolds in the tank vault 20 (e.g., by transition fittings 30 through a wall of the tank vault 20) may include any number, size, and/or configuration of energy transfer pipes for transfer of energy from a ground source to a solution that is to be transported to a heat pump apparatus 14 using one or more manifolds in the vault tank 20. In other words, any number of flow circuits and configurations of such flow circuits may be used. For example, as described herein, such flow circuits may include use of one or more fields of piping in vertical wells (e.g., 200 feet to 300 feet vertical wells) or one or more fields of piping in horizontal trenches (e.g., multiple acres of horizontal loop fields). Such fields may vary in the number of wells (e.g., ranging from 20 to 2000 wells) and configuration of piping used.

Further, for example, such systems may use any size of piping and configuration thereof to be connected to the manifolds within the tank vault 20. For example, as described herein, pipes (e.g., 1 inch pipes) may be inserted into a well, or laid in horizontal trenches, to gather or transfer heat via a circulated fluid solution (e.g., glycol solution in the 1 inch pipes). These pipes (e.g., 1 inch pipes) may be provided for connection to the manifolds in the tank vault 20 or, for example, such piping may be brought together (e.g., near finish grade) and tied together into circuit feeder lines (e.g., lines slightly larger than 1 inch piping). For example, such circuit lines may be, for example, 2 inch diameter piping, 3 inch diameter piping, or 4 inch diameter piping) and may be provided for connection to the manifolds in the tank vault 20.

As used herein, energy transfer pipes may refer any pipes or tubes used for the transfer of energy between the ground and the piping and/or pipes used for transport of solution to the tank (e.g., piping in horizontal or vertical wells, pipe used in circuit feeder lines, pipe to be connected to transition fittings of tank vault 20, etc.).

The one or more energy transfer pipes may be formed of any type of material. However, in many cases polymer materials are used to provide such pipes, such as thermoplastic or thermoset materials. Further, for example, such energy transfer pipes may be formed of polyethylene materials, such as non-cross linked polyethylene or cross linked polyethylene. Still further, in one or more embodiments, the piping is formed using high profile high density polyethylene (HDPE).

One embodiment of a tank vault 20, for example, to enclose one or more manifolds (e.g., upstream/downstream manifolds 92, 93), is shown in FIGS. 3A-3D and FIGS. 4A-4C. The tank vault 20 includes a tank shell 22. The tank shell 22 includes at least a cylindrical wall 24 extending along an axis 33 of the tank vault 20 and terminating in two dome-shaped ends 26, 28. The tank shell 22 defines an interior volume 86 in which components of a geothermal exchange system may be positioned (e.g., such as the manifolds 92, 93 described herein). Further, the cylindrical wall 24 and/or the dome-shaped ends 26, 28 may be formed primarily of a FRP material (e.g., one or more other materials may be used between one or more layers of FRP material such that the entire wall may not be FRP). At least one access opening 40 sized to permit a person to enter the tank shell 22 is provided.

The tank vault 20 may be provided in any various sizes. For example, the interior volume 86 of the tank vault 20 may have a capacity of 6000 gallons, 8000 gallons, 10,000 gallons, or 12,000 gallons. However, the present disclosure is not limited to any particular size, although some sizes may be more beneficial than others.

An arrangement of transition fittings 30 located in the cylindrical wall 24 of the tank shell 22 are configured according to the one or more manifolds 90 located within the tank vault 20 as best shown in FIGS. 4A-4C. For example, one or more manifolds 90 (e.g., upstream and downstream manifolds 92, 93) are positioned within the interior of the tank vault 20 as shown in FIGS. 4A-4C. Such manifolds 90 include a plurality of ports 91. Generally, at least a plurality of the ports 91 for each manifold are aligned. For example, ports 91 of manifold 93 are linearly aligned. Of course, the number of ports 91 will vary (e.g., there may be more than five aligned ports, there may be more than ten aligned ports, etc.).

Generally, the ports 91 of the one or more manifolds 90 are positioned within the tank vault 20 and are linearly aligned along the cylindrical wall 24 (e.g., aligned linearly in the same direction and parallel with the axis 33 of the tank vault 20). The ports 91 are generally positioned to allow coupling thereof to the heat exchange pipes of the one or more flow circuits 16 by the arrangement of the plurality of transition fittings 30. As such, the arrangement of the transition fittings 30 is configured so that ports 91 can be coupled to the transition fittings 30, and is also configured so that the heat exchange pipes of the one or more flow circuits 16 can be coupled to the arrangement of the plurality of transition fittings 30.

The position, number and configuration of transition fittings 30 will depend on the configuration of the geothermal system (e.g., number of energy transfer loops, number of circuit feeder lines, manifold size and configuration, etc.). For example, a transition fitting 30 may be positioned in the cylindrical wall 24 adjacent each of the ports 91 such that the port 91 can be fluidly connected to an energy transfer pipe of the one or more flow circuits. In other words, the number and size of the transition fittings 30 may depend on the number and size of the ports 91, as well as the number and size of the energy transfer pipes to be coupled thereto through the cylindrical wall 24. It is understood that the number of the flow circuits can vary as well as the size of the one or more manifolds 90, and the number of ports 91.

As shown in FIGS. 3A-3D and FIGS. 4A-4C, one exemplary arrangement of the plurality of transition fittings 30 located in the cylindrical wall 24 of the tank shell 22 (e.g., configured to couple the plurality of energy transfer pipes to the one or more manifolds 90 within the tank vault 20) includes transition fittings 30 linearly aligned along the cylindrical wall 24 (e.g., aligned along a line parallel to the axis 33 of the tank vault 20). Further, for example, such aligned fittings 30 are positioned at the side of the tank vault 20 when the tank vault 20 is positioned for use. For example, access 40 to the tank vault 20 as shown in the Figures is at the top 123 of the tank vault 20 when in use. As such, the sides of the tank vault are provided by the arc portions 127 and 129 of the cylindrical wall 24 extending 180 degrees from the top 123 of the tank vault 20 to the bottom 125 of the tank vault 20. Further, in one or more embodiments, the aligned fittings 30 are positioned at the side of the tank vault 20 in arc portions lying between 45 degrees and 90 degrees from the top 123 of the vault tank 20 (e.g., arc portions 137, 139) when positioned for use.

Each of the plurality of transition fittings 30 may include, for example, a transition pipe 60 connectable to one of the plurality of energy transfer pipes (e.g., a transition pipe formed of a polyethylene material for ease in coupling to a polyethylene heat transfer pipe) and connectable to a port 91 of the one or more manifolds 90 within the tank vault 20. Each transition fitting 30 provides for a water tight seal at the cylindrical wall 24 of the tank shell 22 between the transition pipe 60 and the cylindrical wall 24 that is formed of FRP material. In one or more embodiments, the transition pipe 60 generally extends into the tank vault 20 a certain distance and extends out of the tank vault 20 a certain distance. As shown in FIG. 4C, the transition pipe 60 extends through the cylindrical wall 24 in a generally horizontal direction (e.g., orthogonal to an axis that extends vertically through the top 123 and bottom 125 of the tank vault 20).

In one more embodiments, the tank vault 20 may be formed in a manner like, and have a tank shell 22 similar to, an underground storage tank (e.g., an underground storage tank used to store liquids, like corrosion-resistant tanks constructed of fiberglass and resin, generally referred to as fiber reinforced plastic, or FRP and available, from, for example, Xerxes Corporation). For example, such a tank shell 22 may be a single wall tank shell, a double wall tank shell, a triple wall tank shell, and include any number of layers for providing a water free interior environment such that it can be used as a vault for enclosing components of the geothermal exchange system 10. For example, such tank shells may include structure similar to storage tanks, particularly of FRP construction, as described in, for example, U.S. Pat. No. 5,544,974 to Berg et al., entitled “System For Underground Storage and Delivery of Liquid Product, and Recovery of Leakage;” U.S. Pat. No. 5,595,456 to Berg et al., entitled “Water-tight Riser For Underground Storage Tank Manway;” U.S. Pat. No. 5,220,823 to Berg et al., entitled “Double Walled Underground Storage Tank;”U.S. Pat. No. 4,974,739 to Gelin, entitled “Storage Tank and Method of Making a Storage Tank;” U.S. Pat. No. 5,020,358 to Sharp, entitled “Double Walled Fibrous Reinforced Resinous Storage Tanks With Common Rib Supports;” U.S. Pat. No. 5,017,044 to Sharp, entitled “Fibrous Reinforced Resinous Storage Tanks With Strengthened Walls;” U.S. Pat. No. 4,875,361 to Sharp, entitled “Double Walled Storage Tanks With Common Rib Supports;” U.S. Pat. No. 4,739,659 to Sharp, entitled “Double Wall Ribbed Storage Tanks;” U.S. Pat. No. 5,720,404 to Berg et al., entitled “Female-Molded Underground Storage Tank and Method of Making;” and U.S. Pat. No. 6,398,057 to Berg et al., entitled “Triple Walled Underground Storage Tank,” all of which are incorporated herein by reference.

For example, the tank vault 20 may be built using either “male” or “female” construction techniques used to provide underground storage tanks (e.g., FRP underground storage tanks). Further, for example, reinforcement ribs 57 (e.g., circumferential ribs), to provide hoop strength, and resistance to buckling, may be faulted (e.g., such as described in the aforementioned patents). For example, such ribs 57 may be spaced along the cylindrical wall 24 and along axis 33 of the tank vault 20. The ribs 57, for example, may be incorporated at the exterior of the tank vault 20 or at the interior thereof, or at any location therebetween. Further, for example, the reinforcement ribs, may be separate from or be integrally Mimed with the cylindrical wall 24. Such ribs 57 provide for a strong, robust and durable tank.

Still further, as shown in FIGS. 3A-3D and FIGS. 4A-4C, in one or more embodiments, each of the plurality of transition fittings 30 may be located in the cylindrical wall 24 of the tank shell 22 between reinforcement ribs 57 (e.g., circumferential ribs). In other words, the one or more manifolds 90 and the plurality of transition fittings 30 are arranged such that the ports 91 are positioned adjacent a region of the cylindrical wall 24 between the reinforcement ribs 57 and each of the transitions fittings 30 is provided in regions of the cylindrical wall 24 free of the reinforcement ribs 57 (e.g., between adjacent ribs 57).

As fiberglass reinforced plastic (FRP) is relatively light, the tank vault 20 can be prepared at a plant and shipped to an installation site (with or without the one or more manifolds enclosed therein). For example, the tank vault 20 includes one or more lifting lugs 65 for use in lifting, delivering and/or installing the tank vault 20. Further, such FRP material is corrosion resistant and unlikely to develop leaks. As such, a FRP tank vault 20 provides watertight and rustproof construction.

Access to the interior of the tank vault 20, as shown in FIGS. 3 and 4, is provided by manway 40. The manway 40 is provided by an opening 69 cut through the cylindrical wall 24, and possibly one or more ribs 57. The opening 69 is desirably large enough to permit easy access and egress for a person. The opening 69 is surrounded by a manway collar 66, which may again be formed of FRP materials. An access riser 67, of an appropriate height, is coupled to the collar 66 to bring the access to ground level when the tank vault 20 is provided underground. One skilled in the art will recognize that any suitable access which permits the tank vault to function as a water tight area for maintenance and operation of the components housed in the tank vault 20 may be used (e.g., watertight covers, risers, etc.).

Further, as shown in FIGS. 4A-4C, the tank vault 20 may incorporate a ladder 41 proximate the manway 40 to allow a person to gain access to the tank vault 20. Further, a horizontal grate 153 (e.g., an FRP grate) may be provided at a lower portion of the tank vault 20 to allow a person to move in the tank vault 20 more easily.

Further, the tank vault 20 may include various other fittings in addition to the transition fittings 30. For example, fittings 68 and 70 (e.g., FRP pipe sleeves) are provided in dome shaped end 26 and correspond to the inlet 58 and outlet 60 which provide solution transport to, for example, the heat pump apparatus 14. In other words, other fittings may be provided to permit the insertion of and communication with fill pipes, pump lines, pumps, vents, monitoring means and the like. Such fittings may be provided in the same manner as fittings in FRP underground storage tank implementations.

However, unlike conventional fittings, due to the physical properties of polyethylene pipe (e.g., HDPE pipe) used for geothermal exchange systems, certain techniques and components must be used to provide a watertight seal at the tank wall 24 where, for example, an HDPE pipe is to enter the FRP tank vault 20. For example, as further described herein, one transition fitting that may be used includes an FRP sleeve (e.g., with a barbed fitting). For example, this fitting may incorporate a HDPE pipe into the FRP sleeve or a coupling that could be laminated into the FRP tank wall, providing a cost-effective, flexible, manufacturing process to match transitions with the manifold pipe systems enclosed in the tank vault 20. Such a technique may also give the ability to form an exceedingly strong category 1 (CAT 1) bond at the point of HDPE contact. However, as described herein, this and several other various transition fittings capable of providing this watertight seal may be used.

One or more various configurations of transition fittings 30 that may be used are shown and shall be described with reference to FIGS. 5-13. However, for example, as generally shown in the other drawings, such a transition fitting 30 includes a transition pipe 60 (e.g., a polyethylene pipe, such as an HDPE pipe) connectable to one of the plurality of energy transfer pipes of the flow circuits 16 and connectable to a port 91 of the one or more manifolds 90 within the tank vault 20 (e.g., at location 162 as shown in FIG. 4C). The transition pipe 60 may include one or more transition pipes depending on the configuration of the transition fitting 30 (e.g., two pipes fluidly coupled in some manner). Each transition fitting 30 also includes sealing apparatus for providing a watertight seal at the cylindrical wall 24 of the tank shell 22 between the transition pipe 60 and the cylindrical wall 24 (e.g., a wall formed at least in part of FRP material, such as a wall whose exterior surface comprises FRP material).

The transition pipe 60 is compatible with the energy transfer pipes to be easily coupled thereto (e.g., by welding, such as by heat or butt fusing). For example, where the energy transfer pipes are polyethylene pipes (e.g., HDPE pipes), then the transition pipe 60 is formed of the same material. In other words, at least in one embodiment, the transition pipe 60 is formed of the same material as the energy transfer pipes. However, in one or more other embodiments, such materials may be different. For example, at least in one embodiment both the transition pipe 60 and the energy transfer pipe coupled thereto are formed of HDPE.

For example, FIG. 5 shows a perspective view of one exemplary transition fitting 200 that may be used in a tank vault 20 for a geothermal exchange system 10. FIG. 6 shows a side view of a portion of the exemplary transition fitting 200 and FIG. 7 shows a cross-sectional view of a portion of the exemplary transition fitting 200. For example, the transition fitting 200 includes a pipe 260 (e.g., HDPE tubing) extending along an axis 268 thereof between a first end 262 to be positioned within the tank vault 20 and a second end 263 located outside of the tank vault 20 when formed as part of the tank vault 20. The pipe 260 includes an inner surface 275 defining an opening along the axis 268 and an outer surface 274.

The transition fitting 200 further includes apparatus for providing a water tight seal at the cylindrical wall 24 of the tank shell 22 as the pipe 260 passes therethrough. To provide such a water tight seal, the transition fitting 200 includes a sleeve 220 (e.g., a steel tube) having an inner surface 285 defining an opening therethrough sized to provide an interference fit with pipe 260 when inserted therein (e.g., an interference fit between the inner surface 285 of the sleeve 260 and the outer surface 275 of the pipe 260). The sleeve 220 extends from a first end 231 to be positioned within the tank vault 20 and a second end 233 located outside of the tank vault 20 when provided as part of the tank vault 20. Further, as shown in FIG. 7, a backing insert 223 (e.g., a stainless steel cylindrical insert) is sized to be positioned within the pipe 260. For example, backing insert 223 includes an exterior surface 291 size to provide an interference fit with the inner surface 275 of pipe 260. The pipe 260, insert 223, and the tube 220 are press fit together as shown in FIG. 7 to provide a seal meeting the requirements of the Category 1 Gas Fitting Standard. Thus a water tight seal is provided between the pipe 260 (e.g., an HDPE pipe) and the tube 220 (e.g., a steel tube).

Still further, a fitting flange 239 (e.g., a steel fitting plate) is provided for mounting the transition fitting 200 on tank vault 20 with the pipe 260 extending through the cylindrical wall 24. For example, the fitting flange 239 may include either a planar or slightly curved material configured to match the curve of the cylindrical tank wall 24. The fitting flange 239 includes an inner surface 271 to be placed adjacent a portion of the cylindrical wall 24 when the transition fitting 200 is being installed and an outer surface 273 opposite the inner surface 271. The fitting flange 239 lies at a position that is not orthogonal to the axis 268 of the transition fitting 200 along which the pipe 260 extends. The fitting flange 239 may be attached, or otherwise coupled, to the sleeve 220 by any suitable process. For example, a steel tube 220 may be welded to a steel fitting flange 239. The flange 239 may be of any size or shape that facilitates attachment of the transition fitting 200 to the tank vault 20.

When the transition fitting 200 is being installed, the pipe 260 may be inserted into an opening in the cylindrical wall 24. For example, the opening may be sized somewhat larger than the diameter of the sleeve 220 to allow movement of the transition fitting 200 such that the pipe 260 can be more easily coupled to a port 91 of a manifold 90 in the tank vault 20. With the transition fitting 200 in position, the fitting flange 239 may be secured to the cylindrical wall 24 using FRP materials, e.g., by glassing, or, in other words, using conventional FRP processing.

Further, FIG. 8 shows a front perspective view of another exemplary transition fitting 300 that may be used in a tank vault 20 for a geothermal exchange system 10. FIG. 9 shows a side view of the exemplary transition fitting 300 and FIG. 10 shows a cross-sectional view of a portion of the exemplary transition fitting 300 being mounted relative to a cylindrical wall 24 of a tank vault 20. For example, the transition fitting 300 includes a pipe 360 (e.g., an HDPE pipe) extending along an axis 368 thereof between a first end 362 to be positioned within the tank vault 20 and a second end 363 located outside of the tank vault 20 when provided as part of the tank vault 20.

The transition fitting 300 further includes apparatus for providing a water tight seal at the cylindrical wall 24 of the tank shell 22 as the pipe 360 passes therethrough. To provide such a water tight seal, the transition fitting 300 includes a fitting flange 339 (e.g., a fitting plate formed of HDPE). In one embodiment, with the fitting plate 339 being formed of the same polyethylene materials as the pipe 360, they may be easily welded (and sealed to one another) or otherwise sealingly coupled as known in the art. The fitting plate 339 is provided for mounting the transition fitting 300 on tank vault 20 with the pipe 360 extending through the cylindrical wall 24. For example, the fitting flange 339 may be of either a planar or slightly curved configuration to match the curve of the cylindrical tank wall 24. The fitting flange 339 includes an inner surface 371 to be placed adjacent a portion of the cylindrical wall 24 when the transition fitting 300 is being installed and an outer surface 373 opposite the inner surface 371. The fitting flange 339 lies at a position that is not orthogonal to the axis 368 of the transition fitting 300 along which pipe 360 lies.

When the transition fitting 300 is being installed, the pipe 360 may be inserted into an opening 389 in the cylindrical wall 24. For example, the opening 389 may be sized somewhat larger than the pipe 360 to allow movement of the transition fitting 300 such that the pipe 360 can be more easily coupled to a port 91 of a manifold 90 in the tank vault 20. With the transition fitting 300 in position, the fitting flange 339 may be secured to the cylindrical wall 24 using FRP materials 381, e.g., by glassing, or, in other words, using conventional FRP processing. However, since polyethylene material of the pipe 360 does not bond well to the FRP material, a sealing material 385, such as, for example, a one-part moisture cure urethand, may be used between the inner surface 371 of the polyethylene fitting plate 339 and a portion of the cylindrical wall 24 prior to application of FRP materials 381. In such a manner, a seal gasket is provided by the sealing material 385 to provide a watertight seal between the pipe 360 and the cylindrical wall 24.

FIG. 11 shows a perspective view of yet another exemplary transition fitting 400 that may be used in a tank vault 20 for a geothermal exchange system 10. For example, the transition fitting 400 includes a pipe 460 (e.g., an HDPE pipe) extending along an axis 468 thereof between a first end 462 to be positioned within the tank vault 20 and a second end 463 located outside of the tank vault 20.

The transition fitting 400 further includes apparatus for providing a water tight seal at the cylindrical wall 24 of the tank shell 22 as the pipe 460 passes therethrough. To provide such a water tight seal, the transition fitting 400 includes a sleeve 439 (e.g., a sleeve formed of FRP) pressure fit onto the pipe (e.g., a pipe formed of HDPE). For example, such a pressure fit may be provided as described in U.S. Pat. No. 5,211,429 to Charlson et al., entitled “Polyethylene Pipe Junction Device.” For example, the sleeve 439 may include the use of one or more barbs as described in U.S. Pat. No. 5,211,429. The sleeve 439 extends along axis 468 between a first end 431 and a second end 433 located outside of the tank vault 20. At least in one embodiment, the sleeve 439 is formed of FRP to allow glassing of the sleeve onto the cylindrical wall 24.

When the transition fitting 400 is being installed, the pipe 460 may be inserted into an opening in the cylindrical wall 24. For example, the opening may be sized somewhat larger than the pipe 460 to allow movement of the transition fitting 400 such that the pipe 460 can be more easily coupled to a port 91 of a manifold 90 in the tank vault 20. With the transition fitting 400 in position, the sleeve 439 may be secured to the cylindrical wall 24 using FRP materials, e.g., by glassing, or, in other words, using conventional FRP processing. This provides a seal between the FRP sleeve 439 and the cylindrical wall 24.

FIG. 12 shows a perspective view of still yet another exemplary transition fitting 500 that may be used in a tank vault 20 for a geothermal exchange system 10. For example, the transition fitting 500 includes a pipe 560 (e.g., an HDPE pipe) extending along an axis 568 thereof between a first end 562 to be positioned within the tank vault 20 and a second end 563 located outside of the tank vault 20.

The transition fitting 500 further includes apparatus for providing a water tight seal at the cylindrical wall 24 of the tank shell 22 as the pipe 560 passes therethrough. To provide such a water tight seal, the transition fitting 500 includes a sleeve 539 (e.g., a steel male threaded bushing) pressure fit onto the pipe 560 (e.g., a pipe formed of HDPE). For example, such a pressure fit may be provided as described in U.S. Pat. No. 5,211,429. For example, the sleeve 539 may include the use of one or more barbs as described in U.S. Pat. No. 5,211,429. The sleeve 539 (e.g., a steel male threaded bushing) extends along axis 568 between a first end 531 and a second end 533; the second end 533 being a male threaded end. Further, a threaded coupling 580 (e.g., a coupling formed of FRP) is provided. The threaded coupling 580 extends along axis 568 between a first end 581 to a second end 583. The first end 581 is a female threaded end for mating with the male threaded end 533 of sleeve 539.

When the transition fitting 500 is being installed, the pipe 560 may be inserted into an opening in the cylindrical wall 24. For example, the opening may be sized somewhat larger than the pipe 560 to allow movement of the transition fitting 500 such that the pipe 560 can be more easily coupled to a port 91 of a manifold 90 in the tank vault 20. With the transition fitting 500 in position, the threaded coupling 580 may be turned onto the male end 533 of the sleeve 539. The threaded coupling 580 may be secured to the cylindrical wall 24 using FRP materials, e.g., by glassing, or, in other words, using conventional FRP processing.

FIGS. 13A-13B show a perspective view of yet another exemplary transition fitting 600 that may be used in a tank vault 20 for a geothermal exchange system 10, as well as a side view of the transition fitting 600 installed as part of the tank vault 20, respectively. For example, the transition fitting 600 includes a pipe 660 extending along an axis 668 thereof between a first end 662 to be positioned within the tank vault 20 and a second end 663 located outside of the tank vault 20.

The transition fitting 600 further includes structure for use in providing a water tight seal at the cylindrical wall 24 of the tank shell 22 as the pipe 660 passes therethrough. To provide such a water tight seal, the transition pipe 660 of the transition fitting 600 includes an inner wall 659 defining an opening through the transition pipe 660. The transition pipe 660 further includes an outer wall 661 facing opposite the inner wall 659.

As shown in FIG. 13B, the inner wall 659 of the transition pipe 660 (e.g., a dual laminate pipe) includes at least a polymer material such as, for example, high density polyethylene. In other words, the region 679 of the transition pipe 660 adjacent or providing the inner wall 659 includes a polymer material such as, for example, high density polyethylene. Still further, the outer wall 661 facing opposite the inner wall 659 of the transition pipe 660 includes at least fiber reinforced plastic material. In other words, the region 680 of the transition pipe 660 adjacent or providing the outer wall 661 (separated schematically in the FIG. 13B from region 680 by dashed line 681) includes at least fiber reinforced plastic material. At least a portion of the outer wall 661 of the transition pipe 660 is coupled to the cylindrical wall 24 of the tank shell 22 using fiber reinforced plastic material. At least in one embodiment, a portion of the outer wall 661 is glassed onto the cylindrical wall 24, such as in the region 625 about the transition pipe 660, using standard FRP layup processes.

For example, the transition pipe 660 may include a pipe formed of HDPE material with fiber reinforced plastic incorporated or embedded into the HDPE material to provide an outer wall 661 to which fiber reinforced plastic material may be bonded when installing the transition fitting 600. For example, a HDPE pipe may be heated to near molten level, and then it may be wrapped with fiber reinforced plastic material on the outside diameter of the HDPE pipe. This embedded fiber reinforced plastic material is physically tied to the HDPE pipe (e.g., integral therewith forming a dual laminate structure). Standard fiber reinforced plastic layup methods may then be used to bond the dual laminate pipe (e.g., HDPE with fiber reinforced plastic material provided at an outside surface thereof) to the tank walls. Still further, for example, the process may be described as melt embedding a layer of dry woven glass fiber fabric or material to the pipe formed of a polymer such as, for example, HDPE, to literally embed the fabric into the outside diameter of the HDPE (e.g., to depths up to about 50 percent of the thickness of the pipe). For example, such processing may be performed by CPF Dualam (Vancouver).

When the transition fitting 600 is being installed, the pipe 660 may be inserted into an opening in the cylindrical wall 24. For example, the opening may be sized somewhat larger than the pipe 660 to allow movement of the transition fitting 600 such that the pipe 660 can be more easily coupled to a port 91 of a manifold 90 in the tank vault 20. With the transition fitting 600 in position, the transition pipe 660 may be secured to the cylindrical wall 24 using FRP materials, e.g., by glassing, or, in other words, using conventional FRP processing. This provides a seal between the transition pipe 660 and the cylindrical wall 24.

It will be recognized that one or more the transition fittings described herein may be used as part of any tank apparatus for connection of one or more fluid transfer pipes located outside of the tank (e.g., one or more fluid transfer pipes formed of high density polyethylene material for use in carrying fluids) to the interior of the tank apparatus. For example, such transition fittings may be used in tank shells, such as those of underground storage tanks (e.g., an underground storage tank used to store liquids (e.g., water, waste water or any other fluid), like corrosion-resistant tanks constructed of fiberglass and resin, generally referred to as fiber reinforced plastic, or FRP and available, from, for example, Xerxes Corporation). For example, the transition fittings may be used in tank shells such as a single wall tank shell, a double wall tank shell, a triple wall tank shell, or any other tank as described herein, particularly of FRP construction, including those built using either “male” or “female” construction techniques used to provide underground storage tanks or above ground storage tanks (e.g., FRP underground or above ground storage tanks).

For example, in one embodiment, and clearly not limited thereto, the tank apparatus for connection to one or more fluid transfer pipes may be similar to that shown in FIGS. 1-4 (e.g., but without the tank being used for geothermal vault purposes, rather for purposes involving storage of fluids). In such tank apparatus, one or more fluid transfer pipes may be required to provide fluid to or from the interior of the tank apparatus (e.g., pipes formed of high density polyethylene material). Generally, the tank apparatus may include a tank shell (e.g., shell 22 or any other shell configuration formed of FRP material) including at least a cylindrical wall 24 terminating in two ends (e.g., two domed ends 26, 28) and defining an interior volume, wherein the cylindrical wall 24 is formed of fiber reinforced plastic material. Further, in at least one embodiment, one or more transition fittings 20 located in the cylindrical wall 24 of the tank shell 22 of the tank apparatus (e.g., used for the storage of fluids as opposed to being used as a vault) are configured to couple the one or more fluid transfer pipes to the interior of the tank shell 22. Such one or more transition fittings may be, for example, a transition fitting as described with reference to FIGS. 13A-13B, or any of the other fittings.

A method of installing a geothermal vault apparatus 20 for use in a geothermal exchange system 10 includes positioning the vault apparatus 12 in a hole (generally represented in FIG. 1 by reference numeral 31). In one or more embodiments, the vault apparatus 12 (including at least the tank vault 20 and one or more manifolds 90) are constructed at a plant and then the vault apparatus 12 is shipped to a location for installation.

Generally, when constructed, the one or more manifolds 90 are built within the tank vault 20 such that the ports 91 are connected to the transition fittings 30. For example, aligned openings corresponding to the ports 91 may be formed in the cylindrical wall 24 to receive the transition fittings 30. The ports 91 of the one or more manifolds 90 may be coupled to the transition fittings 30 prior to the transition fittings 30 being received in the openings of the cylindrical wall 24 or after the transition fittings 30 are received in the openings of the cylindrical wall 24. Such coupling of manifold ports 91 to the transition fittings 30 is performed in any known manner (e.g., compression fittings, HDPE electro-fusion welding, socket welding, butt fusion welding, etc.).

With the transition fittings 30 received in the openings of the cylindrical wall 24, the transition fittings 30 may be attached to a portion of the cylindrical wall 24 as described herein with respect to the various transitions fittings. For example, such transition fittings 30 may be secured to the cylindrical wall 24 using FRP materials, e.g., by glassing, or, in other words, using conventional FRP processing, as described herein with reference to FIG. 11. In other words, an arrangement of a plurality of transition fittings 30 is located in openings in the cylindrical wall 24 of the tank shell 22. Each of such transition fittings 30 are then connected to provide a water tight seal at the cylindrical wall 24 of the tank shell 22 between the transition pipe 60 (e.g., a polyethylene pipe) of the transition fitting 30 and the cylindrical wall 24 formed at least in part of FRP material.

Further, in one or more embodiments, a ballast system (as represented generally by reference numeral 117 in FIG. 1), may be installed to provide a non-buoyant vault apparatus 12 in the hole 31. For example, any number of ballast systems such as those including the use of dead men and straps may be used. For example, one or more of such ballast systems are described in U.S. Pat. No. 7,337,590 to Burwell et al., entitled “Tank Retaining System”; U.S. Pat. No. 7,028,967 to Burwell et al., entitled “Tank Retaining System”; and U.S. Pat. No. 6,786,689 to Dorris, entitled “Low Profile Deadman and Method for Shipping the Same with a Tank.” However, any ballast system may be used and the present disclosure is clearly not limited to those described herein or in the references cited herein.

Any features, components, and/or properties of any of the embodiments described herein may be incorporated into any other embodiment(s) described herein.

All patents, patent documents, and references cited herein are incorporated in their entirety as if each were incorporated separately. This disclosure has been provided with reference to illustrative embodiments and is not meant to be construed in a limiting sense. As described previously, one skilled in the art will recognize that other various illustrative applications may use the techniques as described herein to take advantage of the beneficial characteristics of the apparatus and methods described herein. Various modifications of the illustrative embodiments, as well as additional embodiments of the disclosure, will be apparent upon reference to this description. 

1. A geothermal apparatus for use in a geothermal system, wherein the geothermal system includes a plurality of energy transfer pipes for transfer of energy from a ground source to a solution to be transported to a heat pump apparatus, the geothermal apparatus comprising: one or more manifolds used in controlling the flow of the solution from the plurality of energy transfer pipes to the heat pump apparatus, wherein the one or more manifolds comprise a plurality of ports; and a tank vault to enclose the one or more manifolds used to control the flow of the solution, the tank vault comprising: a tank shell comprising at least a cylindrical wall terminating in two dome-shaped ends and defining an interior volume, wherein the cylindrical wall comprises a fiber reinforced plastic material; an access opening sized to permit a person to enter the tank shell; and an arrangement of a plurality of transition fittings located in the cylindrical wall of the tank shell and configured to couple the plurality of energy transfer pipes to the plurality of ports of the one or more manifolds enclosed within the tank vault, wherein each of the plurality of transition fittings comprises a transition pipe formed of at least a polymer material connectable to one of the plurality of energy transfer pipes and coupled to one of the plurality of ports of the one or more manifolds, wherein each transition fitting provides for a water tight seal at the cylindrical wall of the tank shell between the transition pipe and the cylindrical wall comprising the fiber reinforced plastic material.
 2. The geothermal apparatus of claim 1, wherein the transition pipe comprises a polyethylene material.
 3. The geothermal apparatus of claim 1, wherein the transition pipe is formed of at least high density polyethylene material and is connectable to an energy transfer pipe formed of high density polyethylene material.
 4. The geothermal apparatus of claim 1, wherein the transition pipe of the transition fitting comprises an inner wall defining an opening through the transition pipe, wherein the inner wall of the transition pipe comprises at least high density polyethylene, and further wherein the transition pipe comprises an outer wall facing opposite the inner wall, wherein the outer wall of the transition pipe comprises at least fiber reinforced plastic material, and further wherein at least a portion of the outer wall of the transition pipe is coupled to the cylindrical wall using fiber reinforced plastic material.
 5. The geothermal apparatus of claim 1, wherein the transition fitting comprises a sleeve formed of a fiber reinforced plastic material or a metal material, the sleeve comprising an inner wall defining an opening through the sleeve, wherein the inner wall of the sleeve is coupled to the transition pipe to provide a water tight seal therebetween, and further wherein the transition fitting comprises a sleeve formed of a fiber reinforced plastic material or a metal material, the sleeve comprising an outer wall coupled to the cylindrical wall using fiber reinforced plastic material.
 6. The geothermal apparatus of claim 1, wherein the transition fitting comprises a sleeve formed of a fiber reinforced plastic material or a metal material, the sleeve comprising an inner wall defining an opening through the sleeve, wherein the inner wall of the sleeve is coupled to the transition pipe to provide a water tight seal therebetween, and further wherein the opening defined by the inner wall lies along an axis of the sleeve, and further wherein the transition fitting comprises a flange extending about the sleeve non-orthogonal to the axis, the flange being coupled to the cylindrical wall of the tank shell using fiber reinforced plastic material.
 7. The geothermal apparatus of claim 1, wherein the transition fitting comprises: a sleeve formed of a metal material, wherein the sleeve comprises an inner wall defining an opening through the sleeve along an axis thereof; an insert configured to be inserted into an opening of the transition pipe, wherein the transition pipe is press fit between the insert and the sleeve; and a flange formed of a metal material extending about the sleeve non-orthogonal to the axis, the flange being coupled to the cylindrical wall of the tank shell using fiber reinforced plastic material.
 8. The geothermal apparatus of claim 1, wherein the transition fitting comprises: a sleeve formed of a metal material, wherein the sleeve comprises an inner wall defining an opening through the sleeve along an axis thereof from a first end to a second to of the sleeve, wherein the second end of the sleeve is threaded, and further wherein the inner wall of the sleeve is coupled to the transition pipe to provide a water tight seal therebetween; and a coupling extending from a first end to a second end, the coupling comprising an outer wall formed of a fiber reinforced plastic material and an inner wall defining an opening for receiving a portion of the transition pipe therein, wherein inner wall of the first end of the coupling is threaded to mate with the second end of the sleeve and the outer wall of the coupling is coupled to the cylindrical wall using fiber reinforced plastic material.
 9. The geothermal apparatus of claim 1, wherein the cylindrical wall extends along an axis of the tank shell between the dome-shaped ends, and further wherein multiple transition fittings of the plurality of transition fittings are linearly aligned along the cylindrical wall parallel to the axis of the tank shell.
 10. The geothermal apparatus of claim 1, wherein the tank shell comprises a single, double, or triple wall tank, and further wherein the tank shell is associated with one or more circumferential ribs spaced along an axis of the cylindrical wall of the tank shell.
 11. A vault apparatus for use in a geothermal system, wherein the geothermal system includes a plurality of energy transfer pipes for transfer of energy from a ground source to a solution to be transported to a heat pump apparatus via one or more manifolds, the vault apparatus comprising: a tank shell comprising at least a cylindrical wall terminating in two dome-shaped ends and defining an interior volume, wherein the cylindrical wall comprises fiber reinforced plastic material; an access opening sized to permit a person to enter the tank shell; and an arrangement of a plurality of transition fittings located in the cylindrical wall of the tank shell and configured to couple the plurality of energy transfer pipes to a plurality of ports of the one or more manifolds, wherein each of the plurality of transition fittings comprises a transition pipe connectable to one of the plurality of energy transfer pipes and connectable to one of the plurality of ports of the one or more manifolds, wherein each transition fitting provides for a water tight seal at the cylindrical wall of the tank shell between the transition pipe and the cylindrical wall comprising the fiber reinforced plastic material.
 12. The vault apparatus of claim 11, wherein the transition pipe comprises a polyethylene material.
 13. The vault apparatus of claim 11, wherein the transition pipe is formed of at least high density polyethylene material and is connectable to an energy transfer pipe formed of high density polyethylene material.
 14. The vault apparatus of claim 11, wherein the transition pipe of the transition fitting comprises an inner wall defining an opening through the transition pipe, wherein the inner wall of the transition pipe comprises at least high density polyethylene, and further wherein the transition pipe comprises an outer wall facing opposite the inner wall, wherein the outer wall of the transition pipe comprises at least fiber reinforced plastic material, and further wherein at least a portion of the outer wall of the transition pipe is coupled to the cylindrical wall using fiber reinforced plastic material.
 15. The vault apparatus of claim 11, wherein the transition fitting comprises a sleeve formed of a fiber reinforced plastic material or a metal material, the sleeve comprising an inner wall defining an opening through the sleeve, wherein the inner wall of the sleeve is coupled to the transition pipe to provide a water tight seal therebetween, and further wherein the transition fitting comprises a sleeve formed of a fiber reinforced plastic material or a metal material, the sleeve comprising an outer wall coupled to the cylindrical wall using fiber reinforced plastic material.
 16. The vault apparatus of claim 11, wherein the transition fitting comprises a sleeve formed of a fiber reinforced plastic material or a metal material, the sleeve comprising an inner wall defining an opening through the sleeve, wherein the inner wall of the sleeve is coupled to the transition pipe to provide a water tight seal therebetween, and further wherein the opening defined by the inner wall lies along an axis of the sleeve, and further wherein the transition fitting comprises a flange extending about the sleeve non-orthogonal to the axis, the flange being coupled to the cylindrical wall of the tank shell using fiber reinforced plastic material.
 17. The vault apparatus of claim 11, wherein the transition fitting comprises: a sleeve formed of a metal material, wherein the sleeve comprises an inner wall defining an opening through the sleeve along an axis thereof; an insert configured to be inserted into an opening of the transition pipe, wherein the transition pipe is press fit between the insert and the sleeve; and a flange formed of a metal material extending about the sleeve non-orthogonal to the axis, the flange being coupled to the cylindrical wall of the tank shell using fiber reinforced plastic material.
 18. The vault apparatus of claim 11, wherein the transition fitting comprises: a sleeve formed of a metal material, wherein the sleeve comprises an inner wall defining an opening through the sleeve along an axis thereof from a first end to a second to of the sleeve, wherein the second end of the sleeve is threaded, and further wherein the inner wall of the sleeve is coupled to the transition pipe to provide a water tight seal therebetween; and a coupling extending from a first end to a second end, the coupling comprising an outer wall formed of a fiber reinforced plastic material and an inner wall defining an opening for receiving a portion of the transition pipe therein, wherein inner wall of the first end of the coupling is threaded to mate with the second end of the sleeve and the outer wall of the coupling is coupled to the cylindrical wall using fiber reinforced plastic material.
 19. The vault apparatus of claim 11, wherein the cylindrical wall extends along an axis of the tank shell between the dome-shaped ends, and further wherein multiple transition fittings of the plurality of transition fittings are linearly aligned along the cylindrical wall parallel to the axis of the tank shell.
 20. The vault apparatus of claim 11, wherein the tank shell comprises a single, double, or triple wall tank, and further wherein the tank shell is associated with one or more circumferential ribs spaced along an axis of the cylindrical body of the tank shell.
 21. A method of installing a geothermal vault apparatus for use in a geothermal system, wherein the geothermal system includes a plurality of energy transfer pipes for transfer of energy from a ground source to a solution to be transported to a heat pump apparatus, the method comprising: delivering a geothermal vault apparatus to a site for installation, wherein the geothermal vault apparatus comprises: one or more manifolds used in controlling the flow of the solution from the plurality of energy transfer pipes to the heat pump apparatus; a tank vault enclosing the one or more manifolds used to control the flow of the solution, the tank vault comprising: a tank shell comprising at least a cylindrical wall terminating in two dome-shaped ends and defining an interior volume, wherein the cylindrical wall comprises a fiber reinforced plastic material; an access opening sized to permit a person to enter the tank shell; and an arrangement of a plurality of transition fittings located in the cylindrical wall of the tank shell and configured to couple the plurality of energy transfer pipes to a plurality of ports of the one or more manifolds enclosed within the tank vault, wherein each of the plurality of transition fittings comprises a transition pipe connectable to one of the plurality of energy transfer pipes and coupled to one of the plurality of ports of the one or more manifolds, wherein each transition fitting provides for a water tight seal at the cylindrical wall of the tank shell between the transition pipe and the cylindrical wall comprising the fiber reinforced plastic material; and positioning the geothermal vault apparatus into a hole at the site.
 22. The method of claim 21, wherein the method further comprises installing a ballast system to provide a non-buoyant vault apparatus in the hole.
 23. The method of claim 21, wherein the transition pipe comprises a polyethylene material to be coupled to an energy transfer pipe also formed of a polyethylene material.
 24. The method of claim 21, wherein the tank shell comprises a single, double, or triple wall tank, and further wherein the tank shell is associated with one or more circumferential ribs spaced along an axis of the cylindrical body of the tank shell.
 25. A tank apparatus for connection to one or more fluid transfer pipes, wherein each of the one or more fluid transfer pipes is formed of high density polyethylene material, the tank apparatus comprising: a tank shell comprising at least a cylindrical wall terminating in two ends and defining an interior volume, wherein the cylindrical wall comprises fiber reinforced plastic material; and one or more transition fittings located in the cylindrical wall of the tank shell and configured to couple the one or more fluid transfer pipes to the interior of the tank shell, wherein each of the one or more transition fittings comprises a transition pipe connectable to one of the one or more fluid transfer pipes, wherein each transition fitting provides for a water tight seal at the cylindrical wall of the tank shell between the transition pipe and the cylindrical wall comprising the fiber reinforced plastic material, and further wherein the transition pipe of the transition fitting comprises an inner wall defining an opening through the transition pipe, wherein the inner wall of the transition pipe comprises at least high density polyethylene, and further wherein the transition pipe comprises an outer wall facing opposite the inner wall, wherein the outer wall of the transition pipe comprises at least fiber reinforced plastic material, and further wherein at least a portion of the outer wall of the transition pipe is coupled to the cylindrical wall using fiber reinforced plastic material.
 26. The tank apparatus of claim 25, wherein the tank shell comprises a single, double, or triple wall tank, and further wherein the tank shell is associated with one or more circumferential ribs spaced along an axis of the cylindrical body of the tank shell. 